Here, \(\hat{1}\)  denotes the unit tensor and \(\otimes \)  denotes the tensor product. This formulation is a variant of the definition of polarity for persistent walks [1]}, [2]}.
In contrast to the latter case [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, the model cell with polarity adhesion exhibits a simple random walk in isolation owing to the absence of the driving term in the expression of free energy in this model. The motility of the cells can only be induced by heterophilic adhesive contact on interfaces of tissues following Eq. (REF )[9]}.
